Except that that is not entirely true. Although not as abandoned as many American city centers, the downtown areas of many a European city was pretty awful during the 80s.

I personally live in a nice picturesque gentrified part of the center of Amsterdam. The building I live in still has the front they added to the original porch to keep out the junkies and homeless in the 80s...

Taking back the city center is a process of the last few decades. The main difference is that there was something worth taking back.